*  * **Shared channels:** read and write a file channel that's shared between
 * multiple operators. Note that although the underlying [FileChannel] may be shared,
 * each [FileOperator] should not be.
 */
internal class FileOperator(
  private val fileChannel: FileChannel,
) {
  /** Write [byteCount] bytes from [source] to the file at [pos]. */
  @Throws(IOException::class)
  fun write(
    pos: Long,

      }

    val fileOperator = FileOperator(file!!.channel)
    fileOperator.write(0, header, FILE_HEADER_SIZE)
  }

  @Throws(IOException::class)
  private fun writeMetadata(upstreamSize: Long) {
    val metadataBuffer = Buffer()
    metadataBuffer.write(metadata)

    val fileOperator = FileOperator(file!!.channel)

    val operator =
      FileOperator(
        randomAccessFile!!.getChannel(),
      )
    val buffer = Buffer()
    operator.read(0, buffer, 5)
    assertThat(buffer.readUtf8()).isEqualTo("Hello")
    operator.read(4, buffer, 5)
    assertThat(buffer.readUtf8()).isEqualTo("o, Wo")
  }

  @Test
  fun write() {
    val operator =
      FileOperator(
        randomAccessFile!!.getChannel(),
      )